Drum



Aug. 27, 1940.

E. HAMEL DRUM Filed Oct. 25, 1937 Patented Aug. 27, 1940 PATENT OFFIQEDRUM Edmund Hamel, Siegmar-Schonau, near Chemnitz, Germany ApplicationOctober 25, 1937, Serial No. 170,989 In Germany November 25, 1936 1Claim.

This invention relates to drums in cross winding frames.

One object of the invention is to prevent the thread from jumping out ofthe groove in which 5 it is guided on the outside of cam drums forproducing cross wound bobbins or cheeses. This tendency to jump is dueto the difference in thread tension which is for instance not the sameat the drum reversing points and in the center between these points.

For this purpose the groove in the surface of the drum has the form of aspiral channel which after one rotation of the drum returns to itsstarting point and, within range of the reversing 5 points, has a depthsufficient to prevent the thread guided on the bottom of the channelfrom being raised up to the surface of the drum. In the center betweenthe reversing points the groove is, on the other hand, so deep that the20 thread portion guided therein has always the same length at anyposition of the drum.

By way of example, the invention is illustrated in the accompanyingdrawing, in which Figure 1 shows a drum having a closed guide 25 groove,one of the reversing stations being shown in section; and

Fig. 2 is a section on the line 2-2, of Fig. 1, showing the differencesin the depth of the thread guiding channel;

Fig. 3 is a section on the line 3-3, of Fig. 2.

Referring to the drawing, the guide drum comprises a cylindrical body Ihaving a closed guide groove 2 which has a relatively low depth withinrange of the reversing stations at 2. The

depth increases, however, toward the center in the direction 2" at whichpoint it is several times as great as at the reversing points. Thisdifference in depth serves for keeping the thread portion guided in thechannel always at the same length, so that the speed of the threadremains constant.

The catch 3 facilitates the insertion of the thread during rotation ofthe drum which may be made of any suitable material. It may further bemade in one piece or composed of two members to suit requirements.

I claim:

A one piece drum for cross winding frames having a groove on itsoutside, said groove having a closed bottom and lateral Walls unitedwith the bottom, said bottom being substantially oval shaped in crosssection, said groove forming a channel which returns to its startingpoint after a rotation of the drum, said groove also having its minimumdepth at the thread reversing points and preventing the thread guided onthe bottom of the channel from being raised by thread tension to thesurface of the drum, and increasing in depth toward the center betweenthe reversing points to maintain uniform length of the thread portionguided in the groove at any position of the drum, said increase in depthof the groove being gradual from the thread reversing point to thecenter of the oval.

EDMUND HAMEL.

